Resistance heating circuit and device

Abstract

The utility model discloses a resistance heating circuit and device, relates to the technical field of resistance heating, and discloses the resistance heating circuit comprising a power supply; the first end of the switching device is connected with the first end of the power supply; the first end of the PTC resistor is connected with the second end of the switching device; and the first end of the resistance device is connected with the second end of the PTC resistor, and the second end of the resistance device is connected with the second end of the power supply. The service life of the resistance heating circuit is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resistance heating, and particularly relates to a resistance heating circuit and device. BACKGROUND

[0002] With the application of resistance heating technology in different fields being more and more extensive, users also put forward higher requirements for the resistance heating circuit.

[0003] The traditional resistance heating circuit is connected with a PTC (Positive Temperature Coefficient) through a contactor to control the power supply, and then the resistance heating is realized through the PTC. This resistance heating circuit has a great defect, that is, the phenomenon of impact current is generated at the moment of starting the resistance heating circuit due to the parasitic capacitance of the PTC itself, that is, the resistance heating circuit will generate impact current at the moment of starting the resistance heating circuit, and then the service life of the whole resistance heating circuit is short (mainly affecting the service life of the devices in the resistance heating circuit).

[0004] The above content is only used to assist in understanding the technical solutions of the present application, and does not represent the acknowledgement of the above content as prior art. CONTENT OF THE UTILITY MODEL

[0005] The main purpose of the present application is to provide a resistance heating circuit and device, which aims to solve the technical problem of short service life of the resistance heating circuit.

[0006] In order to achieve the above purpose, the present application provides a resistance heating circuit, which comprises:

[0007] a power supply;

[0008] a switching device, a first end of the switching device being connected with a first end of the power supply;

[0009] a PTC resistance, a first end of the PTC resistance being connected with a second end of the switching device;

[0010] a resistance device, a first end of the resistance device being connected with a second end of the PTC resistance, and a second end of the resistance device being connected with a second end of the power supply.

[0011] In an embodiment, the switching device comprises an insulated gate bipolar transistor or a field effect transistor.

[0012] In an embodiment, the resistance device comprises a pure resistance heating resistance wire or a pure resistance heating resistance.

[0013] In an embodiment, the power supply includes a power supply positive pole and a power supply negative pole, the first end of the power supply is the power supply positive pole, the second end of the power supply is the power supply negative pole, or the second end of the power supply is the power supply positive pole, and the first end of the power supply is the power supply negative pole.

[0014] In an embodiment, the resistance heating circuit includes:

[0015] a selection switch, an input end of the selection switch is connected with the first end of the resistance device, a first output end of the selection switch is connected with the second end of the resistance device, and a second output end of the selection switch is connected with the first end of the resistance device;

[0016] a key switch, a first end of the key switch is connected with a control end of the selection switch, and a second end of the key switch is connected with the power supply positive pole.

[0017] In an embodiment, the input end of the selection switch is connected with the first output end of the selection switch in conduction and disconnected with the second output end of the selection switch, or the input end of the selection switch is connected with the second output end of the selection switch in conduction and disconnected with the first output end of the selection switch.

[0018] In an embodiment, the resistance heating circuit includes:

[0019] a switch controller, a control end of the switch controller is connected with the third end of the switch device.

[0020] In addition, in order to achieve the above-mentioned purpose, a resistance heating device is also provided, and the resistance heating device includes the resistance heating circuit.

[0021] In an embodiment, the PTC resistance in the resistance heating circuit and the resistance device in the resistance heating circuit are packaged as a PTC heating structure, wherein the first end of the PTC resistance is the first end of the PTC heating structure and is connected with the second end of the switch device in the resistance heating circuit, and the second end of the resistance device is the second end of the PTC heating structure and is connected with the second end of the power supply in the resistance heating circuit.

[0022] In an embodiment, the PTC resistance in the resistance heating circuit is packaged as a PTC heating structure, wherein the first end of the PTC resistance is the first end of the PTC heating structure and is connected with the second end of the switch device in the resistance heating circuit, and the second end of the PTC resistance is the second end of the PTC heating structure and is connected with the first end of the resistance device in the resistance heating circuit.

[0023] The embodiment of the application provides a resistance heating circuit, which comprises a power supply, a switching device, a first end of the switching device being connected with a first end of the power supply, a PTC resistor, a first end of the PTC resistor being connected with a second end of the switching device, and a resistance device, a first end of the resistance device being connected with a second end of the PTC resistor, and a second end of the resistance device being connected with a second end of the power supply. The resistance device is connected with the second end of the PTC resistor and the second end of the power supply, so that the resistance device is connected in the circuit in which the PTC resistor is directly connected with the power supply and the switching device, and then a lower impact current can be generated at the moment when the switching device is closed (i.e. the moment when the resistance heating circuit is started), because the resistance device is always connected in series with the whole resistance heating circuit, and then the influence on the devices in the resistance heating circuit is reduced, especially the influence of thermal stress and voltage stress on the switching device, so that the phenomenon that the impact current is generated at the moment when the resistance heating circuit is started due to the parasitic capacitance of the PTC is avoided, and the use life of the resistance heating circuit is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a frame schematic diagram of the first embodiment of the resistance heating circuit of the application.

[0025] Figure 2 It is a waveform schematic diagram of the PTC in the resistance heating circuit of the application.

[0026] Figure 3 It is an equivalent connection schematic diagram of the resistance heating circuit.

[0027] Figure 4 It is an equivalent connection schematic diagram of the first embodiment of the resistance heating circuit of the application.

[0028] Figure 5 It is an equivalent connection schematic diagram of the second embodiment of the resistance heating circuit of the application.

[0029] Figure 6 It is an equivalent connection schematic diagram of the third embodiment of the resistance heating circuit of the application.

[0030] The implementation, functional features and advantages of the application will be further described with reference to the embodiments and the accompanying drawings.

[0031] Explanation of the reference signs:

[0032] 10 (Vdc), power supply; 20, switching device; 30 (Rp), PTC resistor; 40, resistor device; L, equivalent inductance; C, equivalent capacitance; Q, switching tube; R, equivalent resistance; 110, PTC heating structure; 51, selection switch; 52, key switch; 60, switch controller. DETAILED DESCRIPTION

[0033] It should be understood that the specific embodiments described herein are merely exemplary and not intended to limit the present application.

[0034] In order to better understand the technical solutions of the present application, the following will be described in detail in combination with the drawings of the specification and specific embodiments.

[0035] The existing PTC heating principle is that the PTC effect of barium titanate semi-conductive porcelain is caused by the grain boundary (grain boundary). For conductive electrons, the grain boundary is equivalent to a potential barrier. When the temperature is low, due to the effect of the electric field in barium titanate, the electrons are easy to cross the potential barrier, so the resistance value is small. When the temperature rises to the Curie point temperature (i.e. critical temperature), the internal electric field is destroyed, which cannot help the conductive electrons to cross the potential barrier. This is equivalent to the potential barrier being raised, and the resistance value suddenly increases, producing PTC effect. However, during the production of PTC, a parasitic capacitance is generated. The parasitic capacitance can generate a very high impact current at the moment when the resistance heating circuit is turned on, and a very large impact voltage is generated through the parasitic inductance, thereby causing damage to the components in the resistance heating circuit, affecting the service life and use cost of the resistance heating circuit.

[0036] Therefore, based on the deficiencies of the above resistance heating method, the resistance heating circuit of the present application is proposed: the first end of the resistor device is connected with the second end of the PTC resistor, and the second end of the resistor device is connected with the second end of the power supply, so as to realize the connection of the resistor device in the circuit in which the PTC resistor is directly connected with the power supply and the switching device, thereby a lower impact current can be generated at the moment when the switching device is closed (i.e. the moment when the resistance heating circuit is turned on) (because the resistor device is always connected in series in the whole resistance heating circuit), thereby reducing the influence on the components in the resistance heating circuit, especially the influence of thermal stress and voltage stress on the switching device, thereby avoiding the phenomenon that the impact current generated at the moment when the resistance heating circuit is turned on due to the parasitic capacitance of the PTC itself causes damage to the components in the circuit. This resistance heating circuit generates a lower impact current at the moment when the switching device is closed, thereby reducing the influence on the components in the resistance heating circuit, on the one hand, the standard of component selection for the resistance heating circuit can be reduced to reduce the cost of the whole resistance heating circuit, on the other hand, the components in the resistance heating circuit can be protected from being damaged by the impact current, thereby improving the service life of the resistance heating circuit.

[0037] Based on this, the embodiment of the present application provides a resistance heating circuit, referring to Figure 1 , Figure 1 The figure is a frame schematic diagram of the first embodiment of the resistance heating circuit of the present application.

[0038] Referring to Figure 1 , the present application provides a resistance heating circuit, which comprises:

[0039] a power supply 10;

[0040] a switching device 20, a first end of the switching device 20 being connected with a first end of the power supply 10;

[0041] a PTC resistance 30, a first end of the PTC resistance 30 being connected with a second end of the switching device 20;

[0042] a resistance device 40, a first end of the resistance device 40 being connected with a second end of the PTC resistance 30, and a second end of the resistance device 40 being connected with a second end of the power supply 10.

[0043] Exemplarily, referring to Figure 2 , Figure 2 The figure is a waveform schematic diagram of the PTC in the resistance heating circuit of the present application, in which the abscissa represents the use environment temperature of the PTC, and the ordinate represents the resistance value of the PTC. In the figure, the minimum resistance value Rmin corresponding to the minimum working temperature Tmin is marked; the maximum resistance value Rmax corresponding to the maximum working temperature Tmax is marked; the resistance value R25 corresponding to the normal temperature 25℃ T25 is marked; and the temperature value and the resistance value of the normal working interval, i.e. the lowest working resistance value Rc corresponding to the lowest working temperature Tc and the highest working resistance value Rp corresponding to the highest working temperature Tp, are marked. The PTC can be controlled at the lowest working temperature Tc and the highest working temperature Tp to realize the heating function. Further, the selection of the switching device in the resistance heating circuit is also a key link. The selected switching device should not only be able to withstand the impact current due to the PTC characteristics at the moment of turning on, but also guarantee the service life. At this time, the switching device (such as IGBT (Insulated Gate Bipolar Transistor, Insulated Gate Bipolar Transistor)) can be selected to replace the contactor as the switching device, which can solve the problem that the electric arc generated when the contactor is closed with a resistive load causes the contactor to stick or the service life to end, and has the advantages of small size, low cost, high degree of integration, etc. Because the contactor will have the phenomenon that some contactors stick and cause other contactors not to stick, thereby affecting the normal use of the entire resistance heating circuit. Further, based on the selection of the switching device, an equivalent schematic diagram of the resistance heating circuit is provided, referring to Figure 3 , Figure 3Fig. 1 is a schematic diagram of an equivalent connection of a resistance heating circuit, wherein the equivalent resistance R and the equivalent capacitance C are the equivalent resistance and the equivalent capacitance existing in the PTC resistance Rp, and the equivalent inductance L is the equivalent inductance on the whole resistance heating circuit line, and thus the equivalent circuit diagram of Figure 3 However, the existence of the parasitic capacitance (i.e., the equivalent capacitance in the figure) of the PTC resistance will cause excessive thermal stress and voltage stress of the IGBT, and the cumulative thermal impact of multiple impacts will also have a great adverse effect on the service life of the single tube. Moreover, due to the inevitable existence of the parasitic inductance (i.e., the equivalent inductance in the figure, a virtual inductance formed by factors such as wire) in the circuit, the excessive impact current will be accompanied by the generation of high di / dt, and thus the impact voltage E is:

[0044] E = -L di / dt (1)

[0045] The di / dt will generate an induced electromotive force on the inductance, and the induced electromotive force will be superimposed between the collector and the emitter of the switching device, causing great voltage stress on the switching device. The above various adverse factors will have a great influence on the service life of the switching device and the specification during selection.

[0046] In the embodiment, the first end of the resistance device 40 is connected with the second end of the PTC resistance 30, and the second end of the resistance device 40 is connected with the second end of the power supply 10, so as to realize the connection of the resistance device in the circuit in which the PTC resistance 30 is directly connected with the power supply 10 and the switching device 20 is directly connected. Thus, at the moment when the switching device 20 is closed, since the resistance device 40 is always connected in series in the circuit, there is always a resistance connected across the power supply 10 at the moment of normal opening, which greatly suppresses the current impact caused by the PTC resistance 30 at the moment of opening. At this time, the suppression of the impact current means that the current through the switching device 20 is reduced, and the temperature rise caused by the current is smaller than that of the original PTC structure. In addition, as shown in formula (1) above, the reduction of the impact current is accompanied by the reduction of di / dt in the circuit, and thus the induced electromotive force generated by the di / dt on the parasitic inductance is also reduced, which can reduce the voltage stress on the switching device 20. In the scenario of chopping control, the switching tube needs to be frequently turned on and off, which can effectively prolong the service life of the switching device 20, ensure the service life of the whole resistance heating circuit, and select a switching device 20 with a lower voltage and current rating during device selection, thereby reducing the cost.

[0047] In an embodiment, the switching device 20 includes an insulated gate bipolar transistor or a field effect transistor.

[0048] In an embodiment, the resistance device 40 includes a pure resistive heating resistance wire or a pure resistive heating resistance.

[0049] The switch device 20 can be an insulated gate bipolar transistor or a field effect transistor, and the chopper control can be realized by using the insulated gate bipolar transistor or the field effect transistor, and the influence of the contactor sticking can be avoided. It should be noted that the switch device 20 can be adaptively selected according to actual conditions, for example, when the user does not have special requirements for the efficiency of the switch, the switch device 20 can be a simple button switch or a triode, which is not limited herein. Meanwhile, the resistor device 40 needs to use an ohmic pure resistance heating resistance wire or a pure resistance heating resistance, which is connected in series in the original PTC circuit. The resistance wire or the heating resistance can also be used as a heating source in the scenes of electric defrosting, electric heating, battery heating, and the like, and there is no energy loss. It should be noted that the resistor device needs to be a pure resistance device at this time. If an inductive device is selected, the value of the equivalent inductance will be increased, the influence of the impulse voltage will be increased, the impulse current will be reduced, the equivalent inductance will be increased, and the influence of the impulse voltage cannot be effectively improved.

[0050] In the embodiment, a resistance heating circuit is provided, which includes a power supply, a switch device, a first end of the switch device being connected to a first end of the power supply, a PTC resistor, a first end of the PTC resistor being connected to a second end of the switch device, and a resistor device, a first end of the resistor device being connected to a second end of the PTC resistor, and a second end of the resistor device being connected to a second end of the power supply. The resistance heating circuit is connected by connecting the first end of the resistor device to the second end of the PTC resistor and connecting the second end of the resistor device to the second end of the power supply, so that the resistor device is connected in the circuit in which the PTC resistor is directly connected to the power supply and the switch device. A low impulse current can be generated at the moment when the switch device is closed (i.e., at the moment when the resistance heating circuit is turned on), and the influence on the devices in the resistance heating circuit, especially the influence of thermal stress and voltage stress on the switch device, can be reduced. The phenomenon that the devices in the circuit are affected by the impulse current generated at the moment when the resistance heating circuit is turned on due to the parasitic capacitance of the PTC can be avoided. The resistance heating circuit generates a low impulse current at the moment when the switch device is closed, and the influence on the devices in the resistance heating circuit is reduced. On the one hand, the selection standard of the devices in the resistance heating circuit can be reduced, and the cost of the resistance heating circuit can be reduced. On the other hand, the devices in the resistance heating circuit can be protected from being damaged by the impulse current, and the service life of the resistance heating circuit can be improved.

[0051] Further, based on the first embodiment of the application, the second embodiment of the resistance heating circuit is provided, the power supply 10 includes a power supply positive pole and a power supply negative pole, the first end of the power supply 10 is the power supply positive pole, the second end of the power supply 10 is the power supply negative pole, or the second end of the power supply 10 is the power supply positive pole, and the first end of the power supply 10 is the power supply negative pole.

[0052] In the embodiment, the positive and negative poles of the power supply 10, at this time, there is no mandatory requirement for the positive and negative poles of the power supply 10, that is, the entire circuit can be connected with the switch device 20 at the negative pole of the power supply 10, or connected with the switch device 20 at the positive pole of the power supply 10, that is, the connection order of the power supply 10, the switch device 20, the PTC resistor 30 and the resistor device 40 in the entire resistance heating circuit is not limited, that is, only the resistor device 40 is added to the original resistance heating circuit.

[0053] In an embodiment, referring to Figure 4 , Figure 4 The equivalent connection diagram of the first embodiment of the resistance heating circuit of the application is provided, the resistance heating circuit includes:

[0054] The selection switch 51, the input end of the selection switch 51 is connected with the first end of the resistor device 40, the first output end of the selection switch 51 is connected with the second end of the resistor device 40, and the second output end of the selection switch 51 is connected with the first end of the resistor device 40.

[0055] The key switch 52, the first end of the key switch 52 is connected with the control end of the selection switch 51, and the second end of the key switch 52 is connected with the power supply positive pole.

[0056] Further, the input end of the selection switch 51 is conductively connected with the first output end of the selection switch 51, and disconnected with the second output end of the selection switch 51, or the input end of the selection switch 51 is conductively connected with the second output end of the selection switch 51, and disconnected with the first output end of the selection switch 51.

[0057] In the embodiment, the resistance heating circuit comprises a selection switch 51, and the control logic of the selection switch 51 is controlled based on the pressed and unpressed states of the key switch 52. When the key switch 52 is pressed (the voltage output of the power supply 10 is output to the control end of the selection switch 51), the input end of the selection switch 51 is connected in conduction with the first output end of the selection switch 51 and disconnected with the second output end of the selection switch 51, that is, the resistor device 40 is short-circuited out of the entire resistance heating circuit at this time, because the function of the resistor device 40 is to ensure that the power supply 10 always has a resistance. However, if there is a resistance in the power supply 10 at this time, the user can press the key switch 52 to short-circuit the resistor device 40 out of the entire resistance heating circuit, that is, when the user finds that the device in the resistance heating circuit, such as the power supply 10 or the switch device 20, is in series with a resistance, the user can press the key switch 52. When designing the PTC resistance, the equivalent resistance R has already reached the resistance value requirement of the resistor device 40, for example, the resistance value of the normal resistor device 40 needs A, and the equivalent resistance R of the normal PTC resistance is only B, and B is much smaller than A, so the resistor device 40 needs to be introduced. On the contrary, when the equivalent resistance R of the PTC resistance is only C, and C is much greater than A, the resistor device 40 does not need to be added, thereby the selectivity of the entire resistance heating circuit can be improved. When the user finds that the resistor device 40 needs to be introduced, the key switch 52 is not pressed (assuming that the control end of the selection switch 51 is normally connected when there is no input), the input end of the selection switch 51 is connected in conduction with the second output end of the selection switch 51 and disconnected with the first output end of the selection switch 51, that is, the resistor device 40 is connected to the entire resistance heating circuit at this time, so as to realize the function of reducing the inrush current of the resistance heating circuit in the first embodiment, so as to prolong the service life of the resistance heating circuit by protecting the switch device 20. At the same time, the reduction of the inrush current can reduce the selection standard of the switch device 20 of the user, thereby reducing the cost of the entire resistance heating circuit.

[0058] In an embodiment, the resistance heating circuit comprises:

[0059] A switch controller 60, and a control end of the switch controller 60 is connected with the third end of the switch device 20.

[0060] In the embodiment, since the switching device 20 can be the insulated gate bipolar transistor or the field effect transistor as described above, a switching controller 60 is required to be designed for the whole resistance heating circuit, and then the switching controller 60 controls the on or off of the switching device 20. It is worth mentioning that the third terminal of the switching device 20 generally refers to the gate of the insulated gate bipolar transistor or the field effect transistor, and the first terminal of the switching device 20 can be the drain of the insulated gate bipolar transistor or the field effect transistor, and the second terminal of the switching device 20 can be the source of the insulated gate bipolar transistor or the field effect transistor, or the first terminal of the switching device 20 can be the source of the insulated gate bipolar transistor or the field effect transistor, and the second terminal of the switching device 20 can be the drain of the insulated gate bipolar transistor or the field effect transistor, that is, the second terminal of the switching device 20 and the first terminal of the switching device 20 are not limited, but the third terminal of the switching device 20 must be the control terminal of the switching device 20. At this time, the on or off of the switching device 20 can be controlled based on the intermittent high and low level (that is, the output of the switching controller 60, the switching controller 60 can be a device for waveform generation, or a switch connected to a high point level, and then the switching is connected to the high and low level to realize the output of the high and low level), or a specific waveform can be output, such as a square wave, to control the on or off of the switching device 20, and the control logic of the switching controller 60 to the switching device 20 is not limited here.

[0061] Based on the first embodiment and / or the second embodiment of the resistance heating circuit, the application further provides a resistance heating device 100 (not marked in the figure), which comprises the resistance heating circuit as described above.

[0062] It is worth mentioning that the resistance heating device (the specific structure of the resistance heating device is not limited here, and the resistance heating device at least includes the above resistance heating circuit) according to the embodiment of the utility model, the first end of the resistance device is connected with the second end of the PTC resistance through the resistance device, and the second end of the resistance device is connected with the second end of the power supply, so as to realize that the resistance device is connected in the circuit in which the PTC resistance is directly connected with the power supply and the switching device, and then a lower impact current can be generated at the moment when the switching device is closed (that is, the moment when the resistance heating circuit is started), because the resistance device is always connected in series in the whole resistance heating circuit, and then the influence on the devices in the resistance heating circuit is reduced, especially the influence of thermal stress and voltage stress of the switching device, so that the phenomenon that the impact current is generated at the moment when the resistance heating circuit is started due to the parasitic capacitance of the PTC itself and the influence on the devices in the circuit is avoided. The resistance heating circuit generates a lower impact current at the moment when the switching device is closed, and then the influence on the devices in the resistance heating circuit is reduced, which can reduce the selection standard of the devices in the resistance heating circuit on the one hand, so as to reduce the cost of the whole resistance heating circuit, and on the other hand, the devices in the resistance heating circuit can be protected from being damaged by the impact current, and then the service life of the resistance heating circuit is improved.

[0063] The device provided by the application provides a new resistance heating circuit to ensure the service life of the resistance heating circuit. Compared with the prior art, the device provided by the application has the same beneficial effects as the resistance heating circuit provided by the above-mentioned embodiment, which will not be repeated here.

[0064] Further, based on the first embodiment of the application, the second embodiment of the resistance heating device of the application is proposed, which is described with reference to Figure 5 , Figure 5 The equivalent connection diagram of the second embodiment of the resistance heating circuit of the application is shown in the figure, the PTC resistance 30 in the resistance heating circuit and the resistance device 40 in the resistance heating circuit are packaged as a PTC heating structure 110, wherein the first end of the PTC resistance 30 is taken as the first end of the PTC heating structure 110 and is connected with the second end of the switching device 20 in the resistance heating circuit, and the second end of the resistance device 40 is taken as the second end of the PTC heating structure 110 and is connected with the second end of the power supply 10 in the resistance heating circuit.

[0065] In the embodiment, in the resistance heating device, the PTC resistor 30 in the resistance heating circuit and the resistor device 40 in the resistance heating circuit can be packaged as the PTC heating structure 110, at this time, the PTC resistor 30 and the resistor device 40 can share the heat dissipation or other functions in the PTC heating structure 110, and then there is no waste of resources of the power supply 10 (the heat of the resistor device 40 is also normally transmitted to achieve heating). That is, at this time, the first end of the PTC resistor 30 is used as the first end of the PTC heating structure 110, and is connected with the second end of the switching device 20 in the resistance heating circuit, the second end of the resistor device 40 is used as the second end of the PTC heating structure 110, and is connected with the second end of the power supply 10 in the resistance heating circuit, that is, when designing the PTC heating structure 110, the resistor device 40 is packaged into the PTC heating structure 110 to form a new PTC heating structure 110, and then the effect of directly suppressing the inrush current based on the PTC heating structure 110 can be achieved to improve the service life of the PTC heating circuit. That is, using the above PTC heating structure 110, the inrush current can be effectively suppressed to an acceptable level, the current stress and thermal stress on the IGBT can be greatly reduced, and in the scene of frequent switching such as chopping control, the IGBT single tube will not fail due to thermal accumulation.

[0066] In an embodiment, referring to Figure 6 , Figure 6 is an equivalent connection diagram of the third embodiment of the resistance heating circuit of the present application, the PTC resistor 30 in the resistance heating circuit is packaged as the PTC heating structure 110, wherein the first end of the PTC resistor 30 is used as the first end of the PTC heating structure 110, and is connected with the second end of the switching device 20 in the resistance heating circuit, and the second end of the PTC resistor 30 is used as the second end of the PTC heating structure 110, and is connected with the first end of the resistor device 40 in the resistance heating circuit.

[0067] In the embodiment, the PTC resistor 30 in the resistance heating circuit can be packaged as the PTC heating structure 110, that is, the PTC heating structure 110 still uses the existing packaging mode, but at this time, in order to avoid the influence of the inrush current, the resistor device 40 is added to the original resistance heating circuit to suppress the inrush current. At this time, the first end of the PTC resistor 30 is connected to the second end of the switching device 20 in the resistance heating circuit as the first end of the PTC heating structure 110, and the second end of the PTC resistor 30 is connected to the first end of the resistor device 40 in the resistance heating circuit as the second end of the PTC heating structure 110. At this time, without changing the existing PTC heating structure 110, the inrush current generated at the moment of starting the resistance heating circuit can be reduced to affect the devices in the circuit, thereby protecting the devices (especially the switching device 20) in the resistance heating circuit from being damaged by the inrush current, and thereby improving the service life of the resistance heating circuit.

[0068] The application also provides a vehicle provided with the above resistance heating device, which can be used in scenes such as electric defrosting, electric heating, and battery heating of the vehicle. By using the resistance heating circuit of the application in the resistance heating device, a lower inrush current can be generated at the moment of closing the switching device (i.e., at the moment of starting the resistance heating circuit) (because the resistor device is always connected in series in the entire resistance heating circuit), thereby reducing the influence on the devices in the resistance heating circuit, especially the influence of thermal stress and voltage stress on the switching device, thereby avoiding the phenomenon that the inrush current generated at the moment of starting the resistance heating circuit due to the parasitic capacitance of the PTC affects the devices in the circuit. The resistance heating circuit of the vehicle can reduce the selection standard of the devices in the resistance heating circuit on the one hand to reduce the cost of the entire resistance heating circuit, and on the other hand can protect the devices in the resistance heating circuit from being damaged by the inrush current, thereby improving the service life of the resistance heating circuit. It should be noted that the resistance heating device of the application can also be provided in other products or devices that have a heating scene, which is not limited herein.

[0069] The above only describes some embodiments of the application, and does not limit the patent scope of the application. Any equivalent structural transformation based on the technical concept of the application, or direct / indirect application in other related technical fields is included in the patent protection scope of the application.

Claims

1. A resistance heating circuit, characterized in that, The resistance heating circuit includes: power supply; A switching device, wherein a first terminal of the switching device is connected to a first terminal of the power supply; A PTC resistor, wherein the first end of the PTC resistor is connected to the second end of the switching device; A resistor, wherein a first end of the resistor is connected to a second end of the PTC resistor, and a second end of the resistor is connected to a second end of the power supply.

2. The resistance heating circuit as described in claim 1, characterized in that, The switching device includes an insulated gate bipolar transistor or a field-effect transistor.

3. The resistance heating circuit as described in claim 1, characterized in that, The resistive device includes a purely resistive heating resistance wire or a purely resistive heating resistor.

4. The resistance heating circuit as described in claim 1, characterized in that, The power supply includes a positive terminal and a negative terminal. The first end of the power supply serves as the positive terminal and the second end serves as the negative terminal, or the second end of the power supply serves as the positive terminal and the first end serves as the negative terminal.

5. The resistance heating circuit as described in claim 4, characterized in that, The resistance heating circuit includes: A selection switch is provided, wherein the input terminal of the selection switch is connected to the first terminal of the resistor, the first output terminal of the selection switch is connected to the second terminal of the resistor, and the second output terminal of the selection switch is connected to the first terminal of the resistor. A push-button switch, wherein the first end of the push-button switch is connected to the control terminal of the selector switch, and the second end of the push-button switch is connected to the positive terminal of the power supply.

6. The resistance heating circuit as described in claim 5, characterized in that, The input terminal of the selector switch is connected to the first output terminal of the selector switch and disconnected from the second output terminal of the selector switch, or the input terminal of the selector switch is connected to the second output terminal of the selector switch and disconnected from the first output terminal of the selector switch.

7. The resistance heating circuit as described in any one of claims 1 to 6, characterized in that, The resistance heating circuit includes: A switch controller, wherein the control terminal of the switch controller is connected to the third terminal of the switch device.

8. A resistance heating device, characterized in that, The resistance heating device includes the resistance heating circuit as described in any one of claims 1 to 7.

9. The resistance heating device as described in claim 8, characterized in that, The PTC resistor and the resistive device in the resistance heating circuit are packaged into a PTC heating structure. The first end of the PTC resistor serves as the first end of the PTC heating structure and is connected to the second end of the switching device in the resistance heating circuit. The second end of the resistive device serves as the second end of the PTC heating structure and is connected to the second end of the power supply in the resistance heating circuit.

10. The resistance heating device as described in claim 8, characterized in that, In the resistance heating circuit, the PTC resistor is packaged as a PTC heating structure. The first end of the PTC resistor serves as the first end of the PTC heating structure and is connected to the second end of the switching device in the resistance heating circuit. The second end of the PTC resistor serves as the second end of the PTC heating structure and is connected to the first end of the resistive device in the resistance heating circuit.

Images